Battle Jump (Unapproachable East) allows the character to make a charge attack and inflict double damage with his or her strike by jumping down from a height of a least 5 feet above an opponent. This highly potent move both resurrects the old "Flying Kick" double damage with an unarmed strike, but also includes a "crooked charge" feature by implication; any movement, as long as it ends in leaping down, can serve as a charge attack. The monk need not depend on uneven terrain; he or she can gain altitude by dancing up walls or by use of the Jump skill. Combined with the "Sudden Leap" Tiger Claw maneuver (Tome of Battle), which allows the character to make a jump as a swift action, this feat even permits the character, in certain circumstances, to make a full attack at the end of a charge, a la the various "Lion's Charge" buffs. That's a lot of buffing for one feat.

Able Learner (Races of Destiny) allows all skills to cost 1 point, although cross-class skills retain the max level limit.

Acrobatic Strike (PHB II) gives a +4 on attacks on one opponent whom the character has Tumbled past, avoiding an attack of opportunity. Since this is standard operating procedure for the monk (those with drunken master levels need only make a DC 15 Tumble check), it essential functions like a free +4 to attack. Requires 12 ranks of Tumble.

Danger Sense (Miniatures Handbook) allows the character, once per day, to roll two die for initiative and take the better of the two rolls.

Earth Power (Races of Stone), which requires Earth Sense, reduces the cost of manifesting psionic powers by one point when standing on the ground. It's a very powerful ability, and in combination with a Torc of Power Preservation (which does the same thing, without the standing-on-earth restriction) you can manifest powers of one level higher than you would otherwise be able to, as if your manifester level were two higher than it is.

Shape Soulmeld (Totem Avatar) and Open Lesser Chakra (shoulders) (Magic of Incarnum). Everything about (Magic of Incarnum) is difficult to explain, including these feats. The important points are that Open Lesser Chakra requires you to be able to shape a soulmeld (hence the Shape Soulmeld feat), be character level 12th or higher, and grants a die size increase to your natural weapons.

Snap Kick (Tome of Battle) -- like Flurry of Blows and Two-Weapon Fighting, Snap Kick grants one extra attack at the price of a -2 penalty to all attacks made during the round. Unlike those abilities, however, Snap Kick's description specifically states it can be combined with full-round actions, including flurry or the decisive strike variant (which gives double damage to all attacks made before the start of your next turn). This makes it much more useful than Two-Weapon Fighting, which cannot be combined with a flurry attack.

Superior Unarmed Strike gives you +4 to your effective monk level to determine unarmed strike damage. Whether it is worthwhile depends on your DM's fondness for antimagic effects. One the one hand, a Monk's Belt or Monk's Tattoo are easier solutions for getting to 2d10 base. On the other hand, if you are antimagic'd, it would be nice not to have to worry about losing all your damage-dealing abilities in addition to the other problems your character no doubt has in that situation.

Tashalatora (Secrets of Sarlona) allows you to designate a psionic class for which you have the Monastic Training feat. Thereafter, your levels in that class stack with your monk levels for determining unarmed damage, AC bonus, and flurry. In effect, any psionic class can become Psionic Fist-like in its pairing of monk abilities and powers, or Psionic Fist itself can be made to grant flurry progression.

Feat slots are precious and sought-after by every variant described below. Alternatives to the choices selected below, or, if your game uses the action points system, good temporary feats to purchase a use of might include:

Assume Supernatural Ability This allows the monk to assume one of the supernatural abilities of one of his metamorphosis forms. Highly useful.

Improved Natural Attack (claws): If your campaign allows Beast Strike, from Dragon magazine, this is an essential feat, which allows claw or slam damage to be added to your unarmed strike damage. Unfortunately, although the damage of these different types of natural attack can be made to stack (with the use of this feat) they remain separate natural attacks and your Improved Natural Attack feat applies to only one of them (usually, the monk's unarmed strike, because the base damage is higher). However, if you can find a feat slot, you can take the feat a second time and apply it to your claw attacks. Whether this is worthwhile depends on your base claw damage. In the example used for the Overchannel feat, above, this feat would add +4d6 to your claw damage. Multiply that by four or five unarmed strikes per round, and it begins to be significant.

Psicrystal Affinity [Psionic]: If you don't mind having a psicrystal to look after, this feat brings several excellent game benefits. In particular, chose the Nimble personality for a +2 to Initiative (and believe me, you can never have too many Initiative buffs for this offense-focused build).

Multiattack: This feat reduces the penalties for off-hand attack. For the Ultimate Monk, who typically has natural weapons either as a racial feature, as a function of his Metamorphosis power, or via psionic powers (Claws of the Beast, Bite of the Wolf, etc.) this is very helpful. The monk can take his full routine of unarmed strikes as a primary attack (but cannot flurry, unfortunately), and then take all of his natural attacks as secondary attack forms. An 8th-level monk/4th-level psionic fist, for example, could manifest the two powers mentioned above and make the follow full attack: unarmed strike/unarmed strike/claw/claw/bite. Secondary attacks would take a -2 penalty. (Normal: the monk could make the same attack routine, with no penalty to his unarmed strikes (since these never take an off-hand penalty) but would take a -5 to hit on his secondary attacks.)

Expanded Knowledge: This feat is taken by every variant of the Ultimate Monk at least once, to get access to the psion's Metamorphosis power. If you can, it's well worth taking a second and even a third time, to get psion/wilder powers like Telekinetic Maneuver, which allows you to roleplay a Jedi-like martial artist that can push foes around with his mind, or powers like Energy Bolt or Energy Burst (the psion equivalents of Lightning Bolt and Fireball) which allow the Ultimate Monk to emulate the powerful bursts of ki energy unleashed by martial artists in Dragon Ball-Z and other anime sources.

Power Knowledge is an epic psionic feat that grants you knowledge of two more powers (from your class list) up to the highest level you can cast. If you missed some great Psychic Warrior powers in picking your top ten (and you did, inevitably) once you reach epic level, you can use this feat to grab a couple more.

Awesome Blow is very much is the spirit of the Overwhelming Attack fighting style. If your character is Large, it should be considered. By flinging your opponents 10 feet in the direction of your choice (in the wake of a successful melee attack), Awesome Blow allows you to emulate the cinematic motif of the martial arts master's opponents flying in every direction, including straight into the air. Unfortunately, as a standard action, sending a half a dozen enemies flying in an instant is (understandably) precluded.

Vow of Poverty, from the Book of Exalted Deeds, is very appropriate for the Ultimate Monk, exchanging all magic items and most other property (the rule is very strict) for a large number of level-dependent benefits including (many) extra exalted feats, AC bonuses, and other goodies.